It's sure to be picked over, examined with a fine-toothed comb for loopholes, with questions about their motives, etc. but good god damn, it's an improvement. Here is the statement Microsoft should have made from the start. It would have changed everything. As it is, though, it may well help improve their reputation.
Hopefully it will help rescue the company too, changing it from being a closed, predatory, punishment-oriented competitor, to one that wants openness so to truly compete on quality.
Nahhh, I'll believe that part when I see it.
Windows Principles: Twelve Tenets to Promote Competition